Geometric Series 12. Below is a graph of the first 5 terms of a geometric sequence. That is, each term in the sequence has the form an = ar"-1 for some constants a and r. a, =0.25 a = 0.0625 a, = 0.015625 -0.03125 #2= 40.125 (a) (1 pt) Based on the values displayed in the graph, write an expression for $5, the partial sum of the first 5 terms of the infinite geometric series _, an- (b) (2 pts) Find a and r. (c) (4 pts) Does the sum of the infinite geometric series converge or diverge? Explain your answer. If it converges, find its sum